The present invention relates to a shoe insole or midsole unit that utilizes proprioceptive feedback mechanisms in the human body to increase the structural integrity of the human foot.
It is a common belief within the realm of professionals dealing with gait related pathologies that a large majority of persons will, at some time in their lives, suffer some form of gait related pain or dysfunction. It is also well accepted that in the majority of cases the mechanism underlying the pathology, injury, or dysfunction can be biomechanically related to the interface of the foot and ground, during the support phase of the gait cycle.
In simplest terms, peoples' feet, for speculative reasons, are in many cases not functioning in an ideal manner when those persons are walking or running.
Many papers have been presented over the last 40 and more years, in the field of podiatry and biomechanics, that describe, what is believed to be, how the foot should interface with the ground, and what magnitude of motions are characterized as normal. In reaction to these findings the concept of introducing appliances, or orthotics, into footwear to brace against excess motion was introduced.
The essence of these appliances was that a physical obstacle could be placed in the footwear to act as a brace against unwanted motion, as diagnosed by a professional in an associated field. Unfortunately efforts made to brace against unwanted motion are accompanied by disuse of the associated muscles that had at one time either caused the motion, or tried to regulate that motion. These muscles, and/or muscle groups will atrophy, or weaken, simply because they are not being used. This form of disuse atrophy is well documented in relation to both bone and muscle.
The relationship between the amount of unwanted motion and muscle strength are inversely related. That is, the weaker the muscles become, the more of the unwanted movement will occur. The inserted appliances therefore promote a weakening of associated muscles, by acting as a brace, and become an object which the body will become dependent upon. The lifestyle of the affected persons will now be such that non discomfort related walking or running is virtually impossible without the insertion of the appliance into the chosen footwear.
In other fields of medicine it is well accepted that injuries to bones, connective tissue and muscles can be rehabilitated, and that a balance in muscle strength and flexibility is important. It is also well recognized that movement of body segments is essential in increasing both strength and flexibility, and that bracing does not promote this. It is also well accepted in all medical fields that the foot and lower limb are composed of bones, connective tissue, and muscles. In these fields it also is accepted that the human body possesses neuromuscular feedback mechanisms which are such that the body's tendencies are to maintain a homeostatic existence. One of these proprioceptive feedback mechanisms functions on the basis of applied pressure. Applied pressure perpendicular to a muscle body's line of action creates tension in the golgi tendon organ thus stimulating the proprioceptive feedback mechanism. The human body will display tendencies to move away from exerted pressures which are uncomfortable. By utilizing this proprioceptive mechanism it is possible to create an environment in which muscles will strengthen themselves as a means of reducing the applied pressure. This mechanism is utilized in the design of this invention such that the associated musculature of the foot will strengthen itself, thus improving its structural integrity and reducing its dependency on artificial modes of bracing.
It is the object of the present invention to provide a novel approach to providing the foot with a means of attaining normal biomechanical values, while at the same time strengthening the associated foot's structural integrity such that any dependency upon footwear bracing, for pain free gait, is eliminated.
Numerous other devices exist or have been invented but these devices are dependent upon the conventional ideology of bracing the foot, an action felt to encourage musculoskeletal atrophy, as well as create dependencies upon bracing devices, or are simply designed to provide short term comfort. Examples of these are U.S. Pat. Nos. 2,084,455 (Reed), 2,046,190 (Silver), 4,716,662 (Bar), 1,605,985 (Rasmussen), 4,442,612 (Hauser), 3,905,376 (Johnson), 1,676,162 (Schiller), 4,759,357 (Allart), 4,747,410 (Cohen), 4,841,648 (Shaffer), 4,697,361 (Ganter), 4,718,179 (Brown), 4,729,179 (Quist) and 4,360,027 (Frielander). Of equal importance when looking at these devices is the lack of presentation of a concept where principles of proprioceptive feedback are used. Similarly, it is also important to note in the case of said invention, the foot is looked upon, mechanically, as being composed of 5 individual arches, corresponding to the 5 metatarsals, each having an anterior end at a metatarsal head, and a posterior end between the lateral and medial tubercles of the calcaneus. These 5 arches intersect at a common point creating a dome structure within the foot itself. The common point of intersection is the articulation of the cuboid, navicular, and lateral cuneiform bones of the foot. This intersection point will hereinafter be referred to as the "apex of the foot's arch system." The unsupported height of the apex of the foot's arch system allows the foot to function as a dynamic dome structure, never sacrificing structural integrity as it adapts to changes in the ground surface.
Although the concept of bracing has produced some favorable results, these results are dependent upon the use of the appliance, once the appliance has been removed the predisposition to injury is greatly magnified.